France is ready to stop Islamist militants who control northern Mali if they continue their offensive, French President Francois Hollande has said, reports the BBC.
However, Mr Hollande said France would only act under UN authorisation.
He was responding to a plea by Malian President Dioncounda Traore for help to counter a renewed rebel offensive.
Earlier, an emergency meeting of the UN Security Council called for the rapid deployment of an African-led international force to Mali.
Armed groups, some linked to al-Qaeda, took control of northern Mali in April 2012.
They have enforced an extreme interpretation of Islamic law.
Analysts say Western nations are concerned that Mali's north could become a base for terrorists to plan and launch international attacks.
The UN has approved plans to send some 3,000 African troops to Mali to recapture the north but they are not due to arrive until September.
"They (rebels) are trying to deliver a fatal blow to the very existence of this country," Mr Hollande said.
"France, like its African partners, cannot accept this. I have decided that France will respond, alongside our African partners, to the request from the Malian authorities.
"We will do it strictly within the framework of the United Nations Security Council resolution. We will be ready to stop the terrorists' offensive if it continues."
Diplomatic sources said Mr Hollande and Mr Traore would meet for talks in Paris next Wednesday.
Read more of this report from the BBC.